EP 0959567 describes a front-end circuit realized in a portable mobile radio device and designed for at least two mobile radio bands, with an antenna switch that alternately connects an antenna to two different signal paths. In one signal path, a multiplex type filter can be arranged, which has two bandpass filters and separates signals transmitted at different frequencies by guiding these signals to different subpaths provided for the different signals.
A radio band, which is characterized by its center frequency, is assigned to a radio system. The radio band can have transmission and receive bands, which are shifted in frequency and do not overlap. A multiband device is in the position to process data from different radio systems.
For separating mobile radio bands, it is known to arrange additional switches in the diverted signal paths after the first switch in the front-end circuit. The additional switches connect the subpaths of the diverted signal path to the antenna via a first switch.